In an automobile equipped with a curtain airbag device, a curtain airbag is inflated downward along a side surface (a door or pillar, for example) of a vehicle interior upon a side impact or roll-over of a vehicle.
Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 2006-137413) discloses a curtain airbag including a curtain airbag body configured to be inflated with gas from an inflator, and a tie panel disposed on an intermediate portion of the curtain airbag body in the front-rear direction of the vehicle on a side opposite the vehicle interior. Upper and lower portions of the tie panel are sewn to upper and lower portions of the curtain airbag body, respectively. The length between an upper sewn portion and a lower sewn portion of the tie panel is shorter than the length between the upper sewn portion and the lower sewn portion of the curtain airbag body. Thus, as described in [0033] or as illustrated in FIG. 7(c) of Patent Literature 1, the inflated curtain airbag body has a <-like shape or L-like shape when viewed from the side. A triangular prismatic space, which has a triangle shape when viewed from a front or rear side, is defined between the curtain airbag body and the tie panel.
When the curtain airbag body receives the impact of an occupant in the event of a vehicle emergency, the gas in the curtain airbag body flows out and the curtain airbag body deforms such that the size of the triangular prism space decreases. Thus, the curtain airbag absorbs the energy to be transferred to the occupant.